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Immature embryos rescued in sunflower breeding programs represent one of the important procedures for creating a competitive research program. The development of inbred lines in a short period offers a significant advantage, enabling faster adaptation of sunflower hybrids to farmers' needs, including new herbicide technologies, such as existing sulfonylurea- and imidazoline-based treatments or the introgression of new disease-resistant genes. In our research, we initiated immature embryo rescue by harvesting at 168 h, 216 h, 264 h, and 312 h after fecundations. The media used were based on MS (Murashige and Skoog) and supplemented with different concentrations of BAP, NAA, and GA3. For the experiments, three types of genotypes were used: inbred lines, populations, and sunflower hybrids. Our results demonstrated a significant connection between harvest timing, the medium used, and the genotype. The highest survival rates were recorded as up to 81% for hybrids and 71% for inbred lines. For immature embryo rescue, they were obtained at 312 h on MS5—2.0:0.4:0.4 (BAP:NAA:GA3). The genotype, culture medium composition, and harvesting time are essential factors for optimizing the in vitro rescue technique of immature sunflower embryos. The survival rates of immature embryos were significantly influenced by the interaction of these factors. [ABSTRACT FROM AUTHOR]

Immature embryos rescued in sunflower breeding programs represent one of the important procedures for creating a competitive research program. The development of inbred lines in a short period offers a significant advantage, enabling faster adaptation of sunflower hybrids to farmers’ needs, including new herbicide technologies, such as existing sulfonylurea- and imidazoline-based treatments or the introgression of new disease-resistant genes. In our research, we initiated immature embryo rescue by harvesting at 168 h, 216 h, 264 h, and 312 h after fecundations. The media used were based on MS (Murashige and Skoog) and supplemented with different concentrations of BAP, NAA, and GA3. For the experiments, three types of genotypes were used: inbred lines, populations, and sunflower hybrids. Our results demonstrated a significant connection between harvest timing, the medium used, and the genotype. The highest survival rates were recorded as up to 81% for hybrids and 71% for inbred lines. For immature embryo rescue, they were obtained at 312 h on MS5—2.0:0.4:0.4 (BAP:NAA:GA3). The genotype, culture medium composition, and harvesting time are essential factors for optimizing the in vitro rescue technique of immature sunflower embryos. The survival rates of immature embryos were significantly influenced by the interaction of these factors.

Helianthus annus L., known as sunflower, is belong to Asteraceae family. This family is one of the biggest angiosperm plant families in between dicotyledons and cultivated sunflower is an important oil plant all around the world. Chloroplast DNA analysis reveals that the origin of the genus dates back to 4.75 to 22.7 million years ago. Sunflower seeds contain 18% protein, 15% cellulose, 9% water, 14% minerals and carbohydrates. In general, sunflower seeds contain 35% to 50% oil by weight. The oil content of sunflower had been specified from 36.9% to 50.2%. These features have made sunflower an important plant worldwide. In principle, the breeding of sunflowers aims to improve the oil content and to get a plant resistant to disease. All breeding methods both classical and biotechnological methods try to contribute these aims. With the help of technology DNA markers have provided useful information about polymorphism, genetic relatedness, and diversity. Technology advances in breeding, especially the use of molecular markers, offer new strategies to obtain high-yielding and resistant plants through DNA sequences located at a known location on the chromosome. Sunflower has been a model plant in Asteraceae family in molecular marker studies because of its economic importance. Many molecular marker studies have been conducted against biotic and abiotic stress conditions, increase oil content and nutritional value, and water consumption etc. Considering its economic value, current studies on the plant will shed light on future studies and improvements can be observed in many yield criteria such as water consumption, harvest efficiency, resistance to pests. [ABSTRACT FROM AUTHOR]

The sunflower (Helianthus annuus L.) is a fundamental oil-yielding culture for Bulgaria and the world and thus, special attention is paid to it. Various selection methods have been used over the years and as a result of successful breeding programs new sunflower forms, lines (В/А and R) and hybrids (oil and confectionery type) were created in Bulgaria. Some of these new forms have new plant architectonic, different vegetation periods, seeds with different sizes and coloration, high combining ability, resistance to diseases, the parasite Broomrape and some herbicides, high seed oil and fatty acid content, genes for restoration of fertility (Rf genes), and different types of cytoplasmic male sterility (CMS). [ABSTRACT FROM AUTHOR]

This research was conducted to determine the yield and quality characteristics of oil sunflower genotypes as candidates for registration under Konya and Karaman conditions, in four replications according to the "Random Blocks Trial Design". The differences between the cultivars used in both locations of the study in terms of the number of days to bloom, the number of days to physiological maturity, plant height, the diameter of the head, the thousand seed weight, seed moisture, seed yield, oil rate, and oil yield were found to be statistically significant. The number of flowering days of the genotypes was found to be 65.6-60.6 days (H194; P63MM54), the number of days to physiological maturity was 116.9-109.0 days (Tunca; P63MM54), plant height 172.0-143.3 cm (Tunca; H249), head diameter 18.8-15.9 cm (H250; P63MM64), thousandseed weight 43.4-54.2 g (H250; Gibraltar), hectoliter weight 32.3-30.3 kg (P63MM54; H194), seed moisture 7.1-8.4 % (H250; P63MM54, Gibraltar), seed yield 4.37-3.82 t ha-1 (H194; H249), oil rate 47.8-42.9 % (H250; H55), and oil yield 2.04-1.64 t ha- 1 (H250; H249). According to the averages of the locations, it can be argued that the H194, H250, H55, and H5 hybrids that have high seed and oil yield can be successfully grown in regional conditions. [ABSTRACT FROM AUTHOR]

This paper presents the main research works and search results which have been discussed inside the 17th international sunflower conference, held in Cordoba (June 8-12, 2008) and organised by the International sunflower association (ISA). It focusses on five main topics: Breeding and genetics, Pathology, Crop production and physiology, Oil and meal quality, Sunflower production in the world and in Spain.

Background: Argentina has a long tradition of sunflower breeding, and its germplasm is a valuable genetic resource worldwide. However, knowledge of the genetic constitution and variability levels of the Argentinean germplasm is still scarce, rendering the global map of cultivated sunflower diversity incomplete. In this study, 42 microsatellite loci and 384 single nucleotide polymorphisms (SNPs) were used to characterize the first association mapping population used for quantitative trait loci mapping in sunflower, along with a selection of allied open-pollinated and composite populations from the germplasm bank of the National Institute of Agricultural Technology of Argentina. The ability of different kinds of markers to assess genetic diversity and population structure was also evaluated. Results: The analysis of polymorphism in the set of sunflower accessions studied here showed that both the microsatellites and SNP markers were informative for germplasm characterization, although to different extents. In general, the estimates of genetic variability were moderate. The average genetic diversity, as quantified by the expected heterozygosity, was 0.52 for SSR loci and 0.29 for SNPs. Within SSR markers, those derived from non-coding regions were able to capture higher levels of diversity than EST-SSR. A significant correlation was found between SSR and SNP- based genetic distances among accessions. Bayesian and multivariate methods were used to infer population structure. Evidence for the existence of three different genetic groups was found consistently across data sets (i.e., SSR, SNP and SSR + SNP), with the maintainer/restorer status being the most prevalent characteristic associated with group delimitation. Conclusion: The present study constitutes the first report comparing the performance of SSR and SNP markers for population genetics analysis in cultivated sunflower. We show that the SSR and SNP panels examined here, either used separately or in conjunction, allowed consistent estimations of genetic diversity and population structure in sunflower breeding materials. The generated knowledge about the levels of diversity and population structure of sunflower germplasm is an important contribution to this crop breeding and conservation. [ABSTRACT FROM AUTHOR]

Procera Agrochemicals Romania is a company that has developed a program for sunflower breeding in 2004. One of the main goals of this improvement program was to obtain sunflower hybrids resistant to broomrape, in consequence of the fact that Romania has a constantly increasing incidence of soil-areas infested with this parasite. Sunflower hybrid PF100 is a semi-late hybrid that has genetic resistance to broomrape and it has also been genetically improved for resistance to sulfonylurea herbicides SURES-1 and SURES-2, for both male and female lines. PF100 has been tested in the Romanian official network of the State Institute for Variety Testing and Registration during last four years (2005-2008). The results recorded showed that the seed production varied from 2348 kg/ha (Timis County, 2005) to 4604 (Vaslui County, 2006) and the oil content in seeds was between 47 and 51%. In 2008, the highest seed yield of this hybrid (3700 kg/ha) was obtained in the demonstration plots established in Viziru, Braila County (a most heavily infested county in the country) [ABSTRACT FROM AUTHOR]